Carrie/Tear Jerker

The ending of the film, with Sue's dream of visiting Carrie's burned-down house to leave flowers... at least, before she gets grabbed by Carrie's arm. Also, the scene immediately afterwards, which has Sue screaming and thrashing about uncontrollably as her mother attempts to calm her down
How about the sequence of Carrie walking to the stage after being elected prom queen? It's so heartwarming and sad because we know what's going to happen and this is the happiest moment of her life and is about to be ruined.
The scene just before the prank is pulled off makes it even more tragic. Sue visits the prom to see Tommy and Carrie, spots the cord that will dump the pig blood, and tries to warn Miss Collins... who throws her out of the prom just seconds before Chris pulls the cord. The whole thing could have been prevented.
Ms. Desjardin's death in the 1976 film. She's trying to help other students when Carrie targets and pins her against the wall. Ms. Desjardin tries in vain to yell out to Carrie, maybe trying to get through to her. Unfortunately, Carrie had hallucinated everyone (including her) had laughed at her. Probably feeling the ultimate betrayal, she brings down a basketball rims on her, crushing her ribs. At least she survives in the two remakes.